The blowout preventer that failed to stop oil from spewing into the Gulf of Mexico being raised to the surface. ((AP Photo/BP PLC) NO SALES)

(Newser)
–
Investigators may now be able to answer the most elusive question since a rig explosion unleashed the massive Gulf of Mexico oil spill more than four months ago, as they get a close-up view of a key piece of equipment for the first time: Why didn't it stop the oil? A crewman guided a crane today to hoist the 50-foot, 300-ton blowout preventer from a mile beneath the sea. It took about 29 1/2 hours for the blowout preventer to reach the surface of the Gulf.

FBI agents were among the 137 people aboard a vessel waiting to escort the device back to a NASA facility in Louisiana for analysis. There has also been testimony that the blowout preventer didn't undergo a rigorous recertification process in 2005 as required by federal regulators. Recertifying the five-story device requires completely disassembling it out of the water and can take as long as three months to complete However, some have cautioned that the blowout preventer will not provide clues to what caused the gas bubble. And it is possible a thorough review may not be able to show why it didn't work.